feat(ingress): 按处理时间为空扫描信箱，移除水位消费（ACM2-78）

readUnprocessed 替代 ID 水位；去掉 INBOX_CURSOR/cutover-watermark/max-commit-delay 及相关健康与指标。

Co-authored-by: Cursor <cursoragent@cursor.com>

src/main/kotlin/com/gzzn/omms/msgexchange/processing/Pump.kt

@@ -14,7 +14,6 @@ import com.gzzn.omms.msgexchange.domain.ProcStatus
 import com.gzzn.omms.msgexchange.infra.log.TraceLog
 import com.gzzn.omms.msgexchange.infra.metrics.PipelineCounters
 import com.gzzn.omms.msgexchange.infra.persistence.CminmsgInboxRepository
-import com.gzzn.omms.msgexchange.infra.persistence.InboxCursorRepository
 import com.gzzn.omms.msgexchange.infra.persistence.ProcStateRepository
 import com.gzzn.omms.msgexchange.infra.retry.ProcFailure
 import jakarta.inject.Singleton
@@ -38,7 +37,6 @@ import java.util.concurrent.atomic.AtomicLong
 @Singleton
 class Pump(
     private val procState: ProcStateRepository,
-    private val cursor: InboxCursorRepository,
     private val processor: MessageProcessor,
     private val props: PipelineProps,
     private val clock: Clock,
@@ -80,17 +78,6 @@ class Pump(
             sleepQuietly(props.pipeline.pollInterval)
             return
         }
-        // 只领取"已被水位覆盖"的队头（`msgId <= W`）。
-        //
-        // 水位以内的行都是收报按 ID 顺序发现并登记的；水位之外的行只可能来自兼容入口
-        // 直接写 PROC_STATE（它不参与水位）。若允许领取，它就会越过那些尚未入队的较小 ID，
-         // 破坏 FIFO（不变量"只领取已发现的行"，`specification.md` `INV-4`）。这种行在空洞补齐、`W` 追平之后自然可领取。
-        val watermark = cursor.load().committedUpTo
-        if (head.msgId > watermark) {
-            warnBeyondWatermark(head.msgId, watermark)
-            sleepQuietly(props.pipeline.pollInterval)
-            return
-        }
         val now = clock.instant()
         when {
             head.state == ProcStatus.FAILED && head.attempts >= props.pipeline.maxAttempts -> {
@@ -111,19 +98,6 @@ class Pump(
         }
     }
 
-    /** 上一次"队头在水位之外"告警时的水位值：只在它变化时告警，避免每秒刷屏。 */
-    private val warnedWatermark = AtomicLong(Long.MIN_VALUE)
-
-    private fun warnBeyondWatermark(msgId: Long, watermark: Long) {
-        if (warnedWatermark.getAndSet(watermark) != watermark) {
-            log.warn(
-                "head msgId={} is beyond watermark W={}; waiting for discovery " +
-                    "(row injected by the compat entry point?)",
-                msgId, watermark,
-            )
-        }
-    }
-
     private fun sleepQuietly(d: Duration) {
         if (!d.isNegative && !d.isZero) Thread.sleep(d.toMillis().coerceAtLeast(1))
     }